Developing good dental hygiene is especially important for children. On a recent Mayo Clinic Radio show, Thomas Salinas, D.D.S., was a guest expert and he discussed dental health topics, from cavities and canker sores to larger issues such as cleft palates or implants. During the radio program listeners tweeted specific questions and below are Dr. Salinas' answers.

Q: Is brushing twice important? Can we use oral chemicals to rinse mouth at night?A: Assuming twice a day brushing (YES!) and you can use chlorhexidine or cetylpyridinium before bed.

Q: What is the most effective toothpaste?A: All fluoridated toothpastes with ADA seal are effective.

Q: Won't 4 minutes of brushing wear down enamel over time?A: 4 minutes of brushing will not appreciably wear down enamel.

Q: How important is the direction you brush? Which area of mouth needs more attention?A: Angle brush 45 degrees to gum with small circular strokes. Spend slightly more time on back teeth.

Q: Isn't fluoride harmful? Why put it in water?A: Fluoride in small quantities as suggested is harmless. 1 part per million is harmless and beneficial.

Q: How do I get rid of gingivitis for good?A: Strong attention to regular oral hygiene with disclosing dye, low sugar consumption, regular professional cleanings.

Q: After two extractions, I have painful teeth and gums when it is cold. Advice?A: Desensitizing toothpastes, bonding over the root surfaces exposed, coverage of the root with crowns, root canal therapy. (Sequentially in that order if each one does not work.)

Q: Will there be stem cell therapy for tooth regeneration?A: There is stem cell regeneration but not refined. Tooth regeneration is still susceptible to decay and periodontal disease. Implants more predictable.